Abnormal putamen morphology Putaminal eye sign 2025-12-18T15:49:31Z An imaging anomly of the putamen that is thought to be pathognomic for MEGDEL syndrome (3-MethylGlutaconic aciduria, Deafness, Encephalopathy, Leigh-like syndrome MIM #614739). In stage 1 of the disease, T2 signal changes of the pallidum are present. In stage 2, swelling of the putamen and caudate nucleus is seen. The dorsal putamen contains an eye that shows no signal alteration and (thus) seems to be spared during this stage of the disease. It later increases, reflecting progressive putaminal involvement. Sparing of the mid dorsal putamen (showing normal signal surrounded by T2 hyperintense signal) is referred to as the putaminal eye.